Motor-driven devices of this type which are configured as motor-driven chain saws have a guide bar for guiding the movement of a saw chain thereon. It is known to equip such motor-driven chain saws also with other tools such as a hedge trimmer, a drilling tool, or the like. Conventional motor-driven chain saws have as standard equipment a lubricating-oil pump feeding lubricating oil from an oil tank to the moving saw chain. When resharpening saw chains and especially back-edge sharpened saw chains, an automatic sharpener is mounted onto the motor-driven chain saw and contamination of the sharpener by leaking lubricating oil must be avoided. Oil lubrication may be unnecessary for another attachment such as a hedge trimmer. The other attachment is fitted to the known motor-driven chain saw by first removing the guide bar, the saw chain and the sprocket cover, and then mounting the driving apparatus for the hedge trimmer or a drilling attachment.
To avoid unnecessary loss of lubricating oil, it has been customary to drain the oil tank prior to mounting and connecting the relevant attachment. Previously, this was accomplished by bringing the motor-driven chain saw into a suitable position for draining, collecting the lubricating oil in a container and then filling it back into the oil tank of the motor-driven saw following refitting of the latter for chain saw operation.
Draining of the oil tank is time-consuming, requires a special container for holding the oil and may result in the loss of oil and, if not properly handled, also may result in contamination of the lubricating oil which is to be filled back into the oil tank after the motor-driven chain saw is refitted to normal chain saw operation.